Separate Zones with LGred Heat Technology and Variable Refrigerant Flow Minisplit System
cbut8995
| Posted in General Questions on
Any opinions on VRF systems for an apt in Brooklyn, NY. It’s new construction. Been looking for something where I can have separate zones within my rooms, have LGred (or any similar like hyper heat), and be able to use the linear slot diffuser for the modern look. Original plan was to have 3 separate concealed ducted mini splits units form Mitsubishi with each of their own outdoor units but it seems that that would be too strong.
any opinions if this VRF system can do and what’s the craze about? I see a lot of Brooklyn apts using it now and even in 1 bedrooms. Not sure what a VRF is different than the standard mini splits with LGred.
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It has to be a heluva HUGE apartment to call for the 3-ton Multi-Vs unit in the link, and it would be an actively BAD idea to oversize either the individual heads/cassettes or the compressor.
That said, LG makes decent cold climate systems and the the Multi-Vs series comes in a number of sizes- a 2 ton MIGHT be appropriate, but it's important to run the load numbers first.
An advantage the Multi-Vs has over a conventional multi-split is that it can simultaneously cool some zones while heating others, applying the heat taken from the cooling zones and putting it directly into the heating zones (rather than outdoors), which can be much more efficient in some applications.
Another advantage for the 4 ton & larger versions of the Multi-Vs is that it can also heat the domestic hot water using their low temp Hydro Kit and a "reverse indirect" water heater as the thermal buffer.
During the cooling season this has huge efficiency advantages- heating most of the water with the heat pulled out of the conditioned space rather than outdoors. But the load of the Hydro Kit exceeds the capacity of the 2 & 3 ton versions. Oversizing the compressor 2-4x for the cooling load just to be able to use the Hydro Kit for the hot water would still deliver a hit in as-used efficiency.
FWIW: I have penciled out a Multi-Vs design for my own home's pre-existing low-temp hydronic heating & domestic hot water system, replacing the current ridiculously oversized 5 ton central-air with a 2 ton air handler running on the Multi-V, which would also heat that ducted zone that is currently delivering 30,000 BTU/hr+ with a hydro air coil in the air handler. (The other heating zones are all radiators & radiant floor micro zones buffered by the reverse indirect water heater.) I haven't had it quoted yet, and I'm not particularly in a hurry- the existing equipment is still working fine (if less than ideal.) A 4 (or maybe 5) ton Multi-Vs would be a relatively easy retrofit.
By the time I'm ready to pull the trigger there may be more competition, and more versions running on less damaging R32 refrigerant rather than R410A available. As of a few months there were R32 versions of the Multi-Vs available, but the only specs I've seen for Hydro Kits were R410A. (In Europe there are several vendors of low temp hydronic heat pumps using R32A, so I'm expecting some of that to show up here eventually...)
A closer fit would be something like:
https://ashp.neep.org/#!/product/25272
This is compatible with their zoning kit (DZK030E4-3):
http://www.daikinac.com/content/commercial/accessories-and-controllers/dzk-zoning-kit-vrv-meets-vav/
A quick read through the manual, it looks like it give you fully modulating zoning, so you get full temperature control for each zone without having to install 3 separate air handlers.
The unit is still oversized for your place, you can do a bit more digging and see if the zoning kit can work with some of the smaller units, probably 12000 BTU is more realistic. Much closer though than a 3 ton unit.